Update to the latest package versions of everything and make sure things work

[joelostblom]

To this in the end. Specifically pay attention to the column names in the Vega movies data sets which were changed recently. Also check if pandas has started to use their string column format by default or if they are still objects.

[joelostblom]

Tag hayley in this PR so that she can check the changes i have made nd do the same in the assignments where needed.

[joelostblom]

I think the movies data set has been changed back nad fourth on vega so we might justwnat to pin the version instead of changing the material until the next release to confirm that we won't have to change it back.